Fuel injection nozzle



May 27, 1947. J. F. HOFFER `FUEL INJECTION NOZZLE 2 Sheets-Sheet 1 g N. VPN

May 27, 1947. J. F. Hol-FER 2,421,329

FUEL INJECTION NozzLE Filed July 8, 1941 2 sheets-sheet 2 lge/kr zines I'fer Patented May 27, 1947 forties n y Y FUEL irimo'rloN,iSrozzLEy n o f, 1 f James F.Hoffer,-Det'r,oit, Mieh.,assignor tofExf Cell-0 Corporation, Detroit, Mich.; a corpora-- j I, y tion ofMichigan` The presentlinvention relates'to improvements in lnozzles adapted* particularly/for delivering timed metered injections of liquid fuel in 'con-L nection withthe operationof internal combus tion engines. Y 'A lOne of the objects of the invention is to provide a 'novel fuel injection nozzle comprising a self-'contained nozzle tip' and filter unit adaptedI to be removably and interchangeably mounted in diierent nozzle holders.

yAnother object is to provide a new andV ima fApplie-atignvJmys, 1941, serial No. 401,499V

3 claim.,A (C1. 21o-ies) Referring o more partielarly tothe drawings, the fuelyinjection nozzle constituting the exem..

plary embodiment cimy invention (Figs. lto 6)` comprises generallyl a` nozzle tip I,`.a .holder 2 .and a filter 3. In the present instance, the noz' zle tip l vandthe holder? lare assembled `in an proved nozzle tip Yand lter unit which isv sealed and tamper-proof so that the unit after proper assembly and adjustment at the source ofrman-l ufacturecannot be subjected V- to maladjustment by inexpertusers .or service men, and so that the unit can be bodily removed from its environment in normal use and handled 'without injury of the working parts and without the entry of dirt and other foreignmatter. y

@another object is to provide a novel ticnper-,proof connectionwhich does `not utilize scr w threads and which must be mutilated in order to separate the parts.' 1

Further objects and advantages will -become apparent as the description proceeds. Y'

In the accompanying drawings, Figure 1 is a longitudinal sectionalview of Aa fuel injection nozzle, andV filter embodying the features of my invention.

Fig.` 2 is a side elevational view on a reduced scale of the nozzle and filter assembly.

Fig. 3 is an enlarged axial view of the nozzle Fig. 4 is a transverse sectional view taken the line 4--4 of Fig. 3.

Fig. 5 is a transversel sectional view taken along line 5-5 of Fig. 3.

along tional view illustrating the the filter.

Fig. 7 is a view similar to Fig. 1f oia modified form of self-contained nozzle and iilter unit.

`While the invention is susceptible of variousy modiiications and alternative constructions, I have shown inthe drawings and will herein de-l scribe in detailthe lpreferred embodiment but it is to be understood that I do not thereby intend to limit the invention to the speciiic form dis- *40 vvFig. 6 is an enlarged fragmentary axial secmeans for= connecting l integral casing structure; and the iilter 3 is permanently and hermetically cor'i'nec'ted tothe base end of the holder in the pathof -fuel Howto theV nozzle tin@` @The nozzle tip L l may l bev 4of any` .suitable type and'fform,"and'preferably comprisesiew V and light worlzingrpartsl qu'lcklyresponsive to pressure changes.' Y.In the present instance, the nozzle tip I is geneerally Alike that disclosed in my copending application Serial No.` 259,088, iiled March 1, 1939, now Patentfzsies, grantedV June 20,V '1944.

fuel injec-V tion nozzle havinga nozzle tip and lter assem`' bd into a self-contained unit by meansof` a In the preferred conStructiomfthe nozzle tip fl and holder Q comprise an elongated tubular shell orosleeve providing an outer casing 4 having ar discharge end and a base end. The 'discharge' end'oi the casing 4 hasA a'bore 5 housing the op-j erati'ng parts "of the nozzle tip I, andthe base end has a slightlvlarger bore 6 throughvwhich' fuel under pressure'isadapted; to be supplied 'to the tip. The casing' is formed with an enlargement 'I having peripheral screw :threads 9 adapted for engagement with a suitable support and defining a clamp shoulder I0.

Tightly tted into the outer end ofthe bore 5 is a cylindrical orifice block Il formed with an axial discharge bore I2. ina peripheral edge notch I4 in the block and is seated in agroove l5 in the bore 5 to-c'onne the' block in position. Closely fitted Within the bore 5 is a tubular valve -seat member I6 having an end wall- Il in 'pressure tight engagement'with the orifice block Il.

nection with the source cfffuel supply, and the Y l2* and coacts ltherewith to define an. annular discharge orice.' By selective variation in the closed, but intend to cover all modifications and alternative constructions fallingrwithin the spirit andscope of the invention as expressed in the:Vv

l sa appended claims.

outer end of this passageisfiformed with an out? wardly facing valve seat`l9` adapted for' corn-V rnunication with the bore l2.

AV pintle 20 extends slidably through the bore form ofthe bore I2"or` the pintle 20, or both, dif-- ferent spray patterns and characteristics may bc obtained as desired to best suit different engine y requirements. In the'present instance, the pintleY 20 is formed inthe shape of a spray control cone 2| movable outwardly to obtain a progressively increasingY orifice area.

a cylindrical valve member 22-slidable the A snap ring `I3 engages o The end wall I l is pro f vided with an axialpassage-I adapted for con-fV The pintle is rigid with' bore I2 and formed at the inner end with an annular valve face 23 adapted for engagement with the seat I9. A peripheral groove 24 is formed in the bore I 2 about the cone 20 and is connected through peripherally spaced longivalve seat I9. It -'will be evident that the vseat I9 and the valve face '23 constitute anl outwardly l opening valve for controlling Athe supply of fuel to the orifice. l f

the valve member 22, and extends axially through the valve seat I9 and'passage i8 into andbeyond the valve 'seat member I6. Fittedsnugly within'the bore 5, in end abutting vengagement with the valve seat member I6, is a thin'fwalled .i ing parts, and against the entry of. foreign matter.

VY tudinaldownow grooves or passages 25 to the-N ,10 An actuating stem 26 is formed integral-with The filter 3 may be of any suitable type or form, and in the present instance is shown as comprising a hollow inverted cup 31 of small granular particles. of bronze sintered together to form a bond. The cup has a peripheral 'end ange 38 abutting against a similar flange 39 on the base end of the holder 2. Fuel filtering through the walls of the cup 31 into the interior is discharged into the bore 34.

To secure the filter 3 permanently and tightly in.. assembled relation with the holder 2, a ringl` `A42 of suitable material, such as copper or v"soft metal, isntightly pressed about the fiangesV3-8 and 39. n One marginal edge of the ring 42*` is bearing sleeve 2l. A valve hangerf28, witl'rfoppo- -f site end anges constituting an elongated guide sleeve slidable Within the bearing sleeve 21, has

' a transverse'wall 29 formed Witha suitable slot in. `interloclrir'igI engagement withf the-` stem 26. More'particularly, the` slot 30 Vhas two enlarged eccentric 4holesfadapted to receive ahead 3l on' the end of the stem 261for assembly, and ej centralportion adapted to engage 4under the head so as to restrain opening movement ofthe valve.` A coiledL compression spring V3'2 encircles the valve stem 2 6, and impinges at oneend against the end wall I1 of the valve seat meinberA I6 and at the other end against the valve hanger 28. The arrangementis ysuch that the spring! tendsto maintain the valve in` closed position with a predetermined pressure, Y Y Y t When'the valve I9, Y23 is`closed`, theguide sleeve 2B is spaced Vfrom the inner end of thevalve lseat member I6. vUpon the supplyof fuel` under pre-y determined valve'opening pressure,the valve member 22 is lifted from the seat I9 against the pressure ofthe spring 32 and the control cone. 2| is moved outwardly. toprogressively increase The; maximum height ,of i

the. orince opening. i rise is determined by engagement of thel hanger or guldesleeve 28. with theinner end of .the valve seat member I6.

Extending through th'e bore of the bodysleeve I 4 is an inner spacer sleeve 33 having Van axial bore 34. and abutting against the bearing sleeve 2l. The various members I6, 21 and 33 are confined in'assembled relation'within the sleevev4.v against the orice block II by thefllter 3 which is rigidly secured'to the baseend of the holder 2 in abutting engagement with the sleevej33.

An important feature of the present invention` resides in'combining'the nozzle tip I and the iilter 3 to form a self-contained sealed unit, In the form Vof Figs. 1 to 6,A the holder also forms a.

part of the unit, but Vit is to be understood that the invention contemplates broadly the self-contained nozzletip and lter construction with and without. thejholderr; In a sense, the tip 'body` insteadof `.beingrnounted-in a separate holder,.is

itself merely elongated and formed with` the threads 9 for securing `the nozzle tip tothe en-V gine. This permits ofva restricted diameterwhich is advantageous and sometimes necessary when the injector is applied to aircraft engines.r 'By locating the lter 3 at. the inlet to the nozzle tip and in permanent fixed relation thereto, instead bent or crimped over the free edge of the flange x38,4 yand the other marginal edge of the ring is` similarly spun or crimped over the free edge of the flange 39. As a result, the holder 2.and the kfilter 3 are rigidly secured together lwith a sealed connection. `To separate the parts so as'to obtain access tothe interior of the nozzle'tip would require mutilation of the ring 42. It will be noted that the connection avoids the use of screw threads which, if provided, would be likely to result in minuteparticles of metal nding their way into the nozzle tip.,l

The self-contained unit (see Fig. 2) is assembled at the factory where theoperating parts of 'the tip are accurately adjusted for correct operation, and where the unit is then sealed by means of the Vtamper-proof connection 42..A The unit can betransported separately,and, being fullyl enclosed, is protected against injury and the entry of dirt. Should the unit require repair or readjustment, it can bebodily-removed from its normal environment and returnedl tothe factory for eX-A pert attention while a replacement unit is employed. In mounting'the unit in place,.the holier 2 .is threaded into the body of the engi-ne,

(not shown) and a lfuel supply conduit or tuff' y 43 is connected to the base end of the 'holderi2 bymeans of Ya hollow'coupling member'44. i f

The coupling Vmernber'44 has a hollow cup 45 on one yend which is threaded onto the base end of the holder 2 in abutting engagement with the flange 38 and which provides a chamber 4S freely enclosing the filter y3. The other end of the member 44`has 'a threaded stem 41 formed with an axial bore or passage 48 opening to the chamber 46 and formed with a tapered counterbore 49.

one end in the counte'rbore 49 by means of a The fuels'upply tube 43 is clamped at sleeve 50. A nut 5Ir embracing the sleeve 50 is threaded onto the stem 4l to complete the assembly.

`In the modied forml of Fig. 7, the self-contained unit consists only of the nozzle tip and Afilter, and is adapted to be replaceably mounted in diierent holders which, in turn, are adapted to be supported on the engine. Except for this dif*- ference, the construction is substantially the same,

' ian'dfnhehce like parts are identied by the same of at some remote point; in the fuel supply line,

any particles of foreign matter dislodged` in the fuel supplyl line are precluded from entering the] nozzle tip and'interfering with the proper func tioning of the delicate working parts. When out of normal environment, the nozzle tip is'protected against injury and rdislocation of the work- One end of theholder 53 is eXterare tightly clampedin assembled relation b v a nut 5G which engages the mounting flange 52 and which is threaded onto the holder. The holder with the attached unit is inserted into the combustion chamber of the engine, and is adapted to be held in position by means of a clamp plate 51 engaging the outer face `of the mounting flange 54. The outer end of the-holder body is connected to the fuel supply Aduct 43 in the same manner as the coupling member 44 of Fig. 1.

The construction of the fuel injection nozzleL independently of the lter is disclosed and oriiice, abutting tubular spacer means in saidsleeve engaging said seat member, .a lter disposed against said base end and serving tov hold. said spacer means in position, means rigidly connecting said filter and said sleeve, and a hollow memA ber threaded onto said base end of said sleeve and enclosing said lter and being adapted for connection to a source of fuel supply.

2. In a fuel injection nozzle, in combination, an elongated sleeve having a base end and, a discharge end, and being formed intermediate its ends with means for connection with a suitable support, means in the discharge end of said sleeve defining a, discharge orifice, valve means includ- ?r ing a stationary tubular valve seat member dis-` posed against said first mentioned means and a -valve for controlling the supply of fuel under pressure through said sleeve to said orifice, abutting tubular spacer means in said sleeve engaging said seat member, a. filter disposed against said base end and serving to hold said spacer means in position, means rigidly connecting said filter and said sleeve, and a hollow member 4 threaded onto said base end of said sleeve and enclosing said filter and being adapted for cony nection to a. source of fuel supply.

3. 1n a fuel injection nozzle, in combination, an elongated sleeve having a base end and a discharge end, and being formed Lintermediate itsV Aends with means for connection with a suitable support, means in the discharge end of said sleeve defining a discharge orifice, valve means including a stationary tubular valve seat member disposed against said first mentioned means'and a valve `for controlling the supply of fuel under pressure through said sleeve to said orifice, abutting tubular spacer means in said sleeve engaging said seat member, a filter disposed against `said base end and serving to hold said spacer means in position, a crimped ring rigidly connecting said filter and said sleeve and requiring mutilation to eiiect separation of said iilter and sleeve, and a hollow member threaded onto said base end of said sleeve and enclosing said filter and being adapted for connection to a source of fuel supply.

JAMES F. HOFFER.

REFERENCES CITED The following references are of record in the ,flle of this patent:

UNITED STATES PATENTS Number Name VDate 2,067,131 Schlaupitz Jan. 5,1937 2,263,197 Tabb et al Nov. 18, 1941 1,835,047 Hill Dec.` 8, 1931 2,146,205 Edwards et al Feb. 7, 1939 2,068,858 Jones Jan. 26, 1937 881,483 Olsen etal Mar. 10, 1908 1,076,128 Kupferle Oct. 21, 1913 2,078,543 Salisbury Apr. 27, 1937 852,584 Skinner May 7, 1907 526,027 Derham Sept. 18, 1894 949,357 Hebbeler Feb. 15, 1910 820,903 Barnes et al May 15, 1906 887,268

Porter et..al. May 12, 1908 

